Pine needle barrier against the dreaded slugs

Here is a picture of my lettuce bed. This year I’m doing a little experiment with it.

The lettuce are called winter destiny and are lovely lettuces. So lovely that the slugs and snails flock from all around to scoff them! So heres the experiment.

I have a wall of pine needles around the bed see if it will work as a barrier to those pesky slime makers. The snails and slugs hate sharp things and will bog off if they cannot through. So I wonder if my pine needle wall will keep them away, time will tell.